1. Field of the Invention
The invention is directed to a concave of an agricultural threshing machine which is pivoted about an axis that is parallel to the axis of the associated threshing cylinder. The concave is provided with an adjustment assembly for adjusting the relative spacing of the concave in relationship to the cylinder. In addition, the concave is pivotally mounted to the side sheets of the threshing machine by a cylindrical bushing that is locked to the concave by a retainer plate.
2. Description of the Prior Art
Typically, harvesting and threshing operations have been combined on a single machine called an agricultural combine. With conventional combines, the threshing cylinder and associated concave are transversely mounted between the side sheets of the combine. The side sheets forming the supporting structure of combine. Harvested grain is transported from the harvesting platform to the threshing means by a feeder house assembly.
The spacing between the threshing cylinder and concave must be adjusted for different crops and crop conditions. The rear of the concave is pivotally mounted to the side sheets whereas the front of the concave may be provided with a spacing adjustment assembly. One type of adjustment assembly currently used on production machines manufactured by the assignee of the present invention, comprises a transverse bar having a square cross section which extends across the front of the concave and which is operatively mounted at both ends to a circular cam, an adjustment arm, and a link assembly. By rotating the circular cam, the adjustment arm moves to concave up and down. The cam, adjustment arm and link are located inside the side sheets of the combine.